execute as @s[tag=!smithingTable.itemSlot] run return run execute as @n[tag=smithingTable.itemSlot,type=marker,distance=..500] at @s run function vs:system/game_ctrol/smithing_table/slot/empty
data modify entity @s item set value {id:"gray_stained_glass_pane",components:{custom_data:{smithingTable:{null:true}}}}